Changed style sheet but source in browser doesnt change

I went into the style sheet of my theme and changed the container size of a header image and the image itself to make it smaller and look more appealing (changing height from 190px to 130px):

#header
{
width: 776px;
margin: 5px auto;
padding:0;
height: 190px;
background: url(http://mysite.com/wp-content/themes/mountain/img/head.jpg) no-repeat top;
border:2px solid #fff;
text-align:right;
}

I edited the style sheet but the change did not render and leaves a gap under the thinner image. When I viewed the source from the browser it showed the old size before the changes. When I examine the style sheet through presentation/edit theme or after downloading from my FTP client it shows the changes have been made.

I’ve cleared out the cache on both IE and Firefox. Why doesn’t it render?

Thanks.